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Mason Jones
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Checked the oil in my 73 and found an ominous yellow/green foam on the dipstick. Looked in the oil canister and it looked like I was making fondue in there. Sooo...I’m guessing I have a blown head gasket (or a cracked block).
 
I’ve got a spare 74 engine that’s been sitting in the garage that I can swap out.  So I’m replacing all the regular maintenance items: timing belt, head gasket, cam cover gaskets, rear main seal, etc. before I install it.
 
My question is on the 74 engine: I removed the rear main seal housing and am not sure if this looks right. There’s a star-shaped plate behind the end of the crankshaft that has the top tang bend over and the bottom tang extends past the end of the housing into the area where the gasket would be. The service manual doesn’t show this very well. Is this the "spray shield"?
 
Seems like that bottom tang would interfere with the gasket making a good seal. Anyone who has done this before know if this is correct? BTW, this is engine has the press in oil seal, not the rope seal.





Last edited on 02-07-2012 09:12 pm by Mason Jones

Mason Jones
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OK, I feel silly now that I see that the star-shaped thing turns pretty easily. I rotated it so the tangs clear the edge of the housing and it looks good. The housing has a gouge in it from being clamped on over that tang. Hopefully it will still seal OK.

Now on to pressing the new main seal in which, from what I've read here, doesn't sound fun.

Greg Fletcher
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The oil shield is installed with a very thin application of silicon sealer and the tang is bent down to keep it in place so it will not move. Installing the lip seal on the auxiliary gasket housing is actually pretty easy, cleaning that engine will be much more work.

Mason Jones
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Greg, thanks for the reply. Sorry for being dense but do you mean put silicon sealer on the oil shield itself (the star shaped thing)? The only part of it that contacts anything are the tips of the tangs which go up against the lip seal when the housing and seal are installed.

Greg Fletcher
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It does contact the block in several places. In the JH factory shop manual, Section A Engine, page 15 describes the installation; Apply a thin coating of Silastic 732 RTV compound to the engine side of the oil thrower, and position it in the cylinder block with the cut out portion in a suitable position to receive the crankshaft (see fig A2).

I would double check the position of your oil thrower. In the photo above it looks to be too far in a clock wise direction.

Mason Jones
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I get it now. I skipped that section of the shop manual because I wasn't planning on removing the crankshaft. I shifted the oil thrower to match the diagram in the manual.

It looks like I'll need to try to get some silicone sealer on the engine side of the oil thrower somehow without removing the crank.



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